Technical Field
This disclosure relates to an image forming apparatus for performing image formation with special color toners in addition to regular color toners.
Related Art
Recent electrophotographic image forming apparatus employ various types of sheets applicable thereto. For example, various types of sheets include special paper such as transparent sheet, sheet having an uneven surface, color paper, and synthetic (waterproof) paper in addition to regular paper such as “plain paper”, “thick paper”, and “coated paper”. To utilize these special papers for image formation, new products including mechanisms and parts different from conventional mechanisms and parts to a fixing unit and a transfer unit are introduced and launched onto the market in response to customer's demands.
Some recently developed image forming apparatuses use special color toner(s) in addition to regular color toners, which are yellow (Y), magenta (M), cyan (C), and black (K) toners. The special color toner includes clear toner (such as transparent toner, colorless toner, achromatic color toner, and no pigment toner) and white toner. The clear toner is supplied over the whole or part surface of a printed medium on which a color image is formed, is adjusted by gross control, so that a high value-added print is generated. The white toner functions as a background of a color image with the cyan, magenta, yellow, and black color toners to be printed on a dark colored paper and a transparent medium.
The above-described image forming apparatuses include four image forming stations for forming respective regular color toner images, i.e., yellow, magenta, cyan, and black color toner images. In addition to these image forming stations, the image forming apparatuses further include another image forming station for forming special color toner images or any one of the regular color toners provided to the respective image forming stations can be replaced with the special color toner.
For example, in order to prevent human errors in setting a printing mode and to provide good quality of printing, known image forming apparatuses include a transmitter to transmit information of type of a printing medium inputted by a user or uses to a database server via a communication network and a receiver to receive the information transmitted by the transmitter. The image forming apparatuses control the image forming operations to be performed in an optimum printing mode selected based on the information received from the data base server by the receiver.
In order to meet customer's demands of high quality printing with specific recording media, manufacturers in the production printing market have previously evaluated recording media (printing media) which are widely known on the market and have distributed the results of evaluation provided in an image forming apparatus in forms of a list or a table of optimized recording media setting database including recommended setting values of the recording media. Consequently, if a user selects data of a printing medium to be used from the setting database table when initiating a print job, an optimum printing quality can be achieved without any consideration and knowledge of operations. Specifically, each of the setting database lists proves data of recording media such that a single brand of a printing medium meets a single optimum print setting of the printing medium.
However, due to an increase in types of toners, these setting values of the setting database list do not achieve the optimum printing quality. For example, in a case in which clear toner is superimposed on a toner image including the cyan, magenta, yellow, and black color toners, an amount of toner on the printing medium increases by the amount of clear toner when compared with the printing medium without the clear toner thereon. To prevent this inconvenience, a fixing temperature, a speed of conveyance of the printing medium, and a transfer current are adjusted. Specifically, an image forming apparatus in which multiple types of special color toners are replaceable in image forming operations is provided with optimum setting values equal to the number of special color toners that are available to a single specific printing medium.
As described above, a single setting data has been sufficient to each printing medium in an image forming apparatus without special color toner(s), which is no longer sufficient when the image forming apparatus includes special color toner(s). Specifically, it is likely that the image forming apparatus using special color toner(s) is prepared and provided with the number of setting data equally corresponding to the number of estimated various ways of printing each printing medium. Therefore, when the image forming apparatus is used, the setting data is changed according to the printing medium to be used and the printing mode, and the settings are complicated and time consuming.